Interconnect-fault-resilient delay-insensitive asynchronous communication link based on current-flow monitoring

Delay-insensitive asynchronous on-chip communication links are a key element to realize a highly reliable asynchronous Network-on-Chip system. However, even a single permanent fault, such as an interconnect fault, causes a deadlock state in the system. This paper presents an interconnect-fault-resilient delay-insensitive asynchronous communication link based on current-flow monitoring. Since current flow upon an interconnect is cut off by an open fault in the interconnect, the current is fed back to a transmitter, which increases a feedback current monotonically. Monitoring the feedback current makes it possible to detect the interconnect fault with delay insensitivity. The proposed link is evaluated by a 0.13μm CMOS technology with a Triple Modular Redundancy (TMR)-based asynchronous communication link which is resilient to the interconnect fault without the delay insensitivity. As a result, the energy consumption and the number of wires of the proposed link are reduced to 57% and 33%, respectively, in comparison with those of the conventional one.